The goal of this program is to improve critical surface parts of artificial joint prostheses through a high quality cover layer of diamond-like carbon (DLC). DLC layers can be produced as hard, smooth coating with a low coefficient of friction. These layers would greatly diminish wear particle burden, a major source of osteolysis and subsequent artificial joint implant failure. We propose to adhere DLC layers to the relevant surfaces of protheses utilizing state-of-the-art physical vapor depsotion (PVD) technology. Although the proposal has relevance to all artificial joint protheses, we will limit work to total hip replacement protheses. It is proposed to demonstrate feasibility of DLC coatings on a variety of implant materials, such as Co-Cr and Ti alloys, zirconia and alumina ceramics, and plastic components made from ultra-high-molecular-weight polyethylene (UHMWPE). During Phase I, feasibility of the proposed improvement of artificial joints will be demonstrated by evaluating DLC deposition parameters generating well- adhering, pinhole-free, and corrosion-resistant coatings, and by estimating their wear resistances and friction coefficients. In Phase II, it is proposed to work with an implant manufacturer and an Orthopedics Department to perform standardized accelerated and long- term wear tests, as well as biocompatibility tests of the deposited DLC coatings, and to evaluate the quality of these implants in vivo in animals. PROPOSED COMMERCIAL APPLICATION: The artificial joint market is a multi-million dollar market, rapidly growing in the U.S., in Europe and in Japan. The proposed improvements would be brought to commercialization in collaboration with established companies. The improvements would increase the lifetime of implants and would provide U.S. companies with a significant competitive advantage in the world market. The novel surface improvements could also increase the lifetime of other implants when used as protective coatings for i.e., heart valves, pacemakers, etc.